SLAC MAGIS-100 Meeting

Monday 20 Feb 2023, 10:00 → 11:30 America/Los_Angeles

84/2-B259 - Group C Conference Room (SLAC)

Zoom meeting
https://stanford.zoom.us/j/96719634497?pwd=WHRzdnRRY29CTXRIN2hRZHNBbjRRQT09
Password: 319682

Group Google Drive Link

Weekly Safety/Coordination meetings, Friday 1:30pm
https://stanford.zoom.us/j/94907288516?pwd=WmdCZjJSQ0RDTGhxQUYzbTRiRXVKQT09
Password: 937502

Weekly Safety Planning Google doc: https://docs.google.com/document/d/1jfImu1nqog_B-BL4jSSsWSZZJfexsPfENRLIu6tjrRs/edit#heading=h.g0y512baojor

Weekly schedule: https://docs.google.com/spreadsheets/d/1GEo-9RMS8jB9jOPpppLY7HZsE43gXey0LAMitwvZLx0/edit#gid=2140641665

MAGIS-100 web page

Norm (ESH coordinator) phone number: 650-996-0301

 

10:00 → 10:10 Distributed Imaging System

Optics
Mechanics
Software
Calibration/Monitoring analysis

Speakers: Ariel Schwartzman (SLAC), Murtaza Safdari (SLAC), Sanha Cheong (Stanford / SLAC)

10:10 → 10:20 Light Field Imaging

• 3D imaging system with panoptical mirror system
• New concepts/ideas
• New applications

Speakers: Ariel Schwartzman (SLAC), Michael Kagan (SLAC), Murtaza Safdari (SLAC), Sanha Cheong (Stanford / SLAC), Sean Gasiorowski (SLAC)

Updates from Jason's lab by Sanha:

(summary of changes at the lab / things that we learned)

1. Vertical imaging beam (incoming from below) set up and aligned. This can turn on to illuminate the atom cloud after the MOT is turned off. Initially set to quite a short duration at 26us.
2. Even at 26us, there "seems" to be a non-trivial upwards momentum kick, resulting in vertically elongated, motion-blurred images (as taken by the lab's existing camera set-up).
3. Furthermore, if the MOT is turned off for a time scale much longer than O(10us), the heat-up and diffusion of the atom cloud is significant.
4. Challenge 1: These two facts together pose an upper-bound on illumination time and therefore brightness that we can image with the MOT turned off.
   1. Aside: Is the time-scale that we should think about for MAGIS-100 as well? How do the atom clouds stay together over O(1s) interferometry sequences without completely diffusing away? Maybe the cooling is better in MAGIS-100?
5. Challenge 2: The atom clouds inherently don't have sharp edges (and are quite big in their sizes), making it difficult for us to test focusing and alignment.

Ideas/Plans to tackle current challenges:

1. Regarding Challenge 1:
   1. The main remaining knob that we can turn from the imaging side is the gain. Further tests with maximal gain setting are needed to confirm whether this brightness issue can be overcome.
   2. Hunter and Sanha also discovered that we get some atoms trapped even with 2 off-axis MOT lasers on and the on-axis MOT laser off. This gives us a steady-state, bright atom cloud, without on-axis beam to be concerned of. We could try to image this "2D MOT" atom cloud instead.
2. Regarding Challenge 2:
   1. Is it possible to reduce the MOT laser's size significantly (simply using apertures)? If so, we could try to create a point-like (or as small as possible) atom cloud and try to focus on this by reducing the "spot sizes" that we see. As of now, the cloud seems too big to be used as a focus reference. This would allow for an "in-situ" focusing.
   2. Hunter and Sanha have briefly discussed the possibility of a different focusing method by placing a test target to the left of the chamber, along the straight line-of-sight direction from the camera/lens. We can still see 10% of the light coming from this direction, and this could be useful. This, however, needs further discussion of what the current largest source of distance uncertainty is.

10:20 → 10:30 Image Processing, Reconstruction, and Simulation

• 3D image reconstruction
• Wave-function phase extraction
• Simulation
• Machine learning methods
• Fourier analysis

Speakers: Michael Kagan (SLAC), Murtaza Safdari (SLAC), Sanha Cheong (STANFORD U., PHYS. DEPT.), Sean Gasiorowski (SLAC)

10:30 → 10:40 Physics Analysis

• Interferometer sequence optimization using AI (detector optimization)
• Systematic uncertainties
• Signal reconstruction and analysis methods for quantum measurements, dark-matter detection, and gravity waves
• Statistical methods
• Physics sensitivity studies

Speakers: Ariel Schwartzman (SLAC), Michael Kagan (SLAC), Murtaza Safdari (SLAC), Sanha Cheong (Stanford / SLAC), Sean Gasiorowski (SLAC)

10:40 → 10:50 Future ideas

• CCD camera with vertical binning readout
• Multi-camera system
• Metalenses

https://docs.google.com/document/d/1JlPQL8C6czchAKfqWAuHjlR7wfZu0E5RbHPMnx1TRvI/edit#